Inventor of the Plek and co-founder of A+D Gitarrentechnologie, Gerd Anke

I did a plek on a Les Paul two years go and it was just a pure pleasure to pick it up and play after. Just wonderful! Still a lot of guitarist never do service on their guitars. Why is it so do you think?

One of the reasons is that they don't know what kind of service is actually possible on a guitar. They don't know what it means to get a setup that suits their own way of playing and they often don’t know where to get it from, or, if they give their guitar to someone, what they will get back. They are often not sure that the repair guy will give them a really good setup. Often it is very difficult to compare. Guitars are difficult to compare if the models are different, or if the players are different. The things that characterize a good setup are often very subjective, personally experienced values.

How do I find out what is the right setup for me personally?

Basically, I find out what the optimal setup is via the strength of the player's attack. Attack determines how much room the strings need to vibrate, and this in turn is what the setup has to take into account so that all the tones of guitar play cleanly, with no buzz anywhere. These values are individual. Every player has a different attack to some degree. And whilst it is possible to assume certain standards that are applicable for most players, it is still basically an individual matter. How you play the strings, how hard, in what places, that ultimately determines the setup of the guitar.

So I need to do this in dialogue with the repair-guy, or the luthier?

Yes, the deciding factor is that the musician knows what is possible so that he or she can then communicate it to the person doing the setup. This means that the setup always proceeds from what suits the individual musician. We often have the situation that this is not the case, because the person doing the setup proceeds from the way he or she plays the guitar, assuming that this is the best way. This is not necessarily the same as what the musician actually needs.

And what does the Plek machine bring to the setup?

A Plek machine offers the possibility of optimizing the physical conditions on a fretboard or on the frets with regard to string action. That means that when a guitar gets Pleked it is adapted to the vibration of the strings in relation to the string action. In the best case all notes sound cleanly. But if the action is too low the strings would buzz a bit everywhere because the attack does not suit the overall setup. For Plek the decisive factor is for the curvature of the neck and the action to be considered as a whole. This means that the higher the action, the greater the curvature, because the strings then need more room to vibrate freely.

Inserting a guitar into the machine

2. How many plek stations are there around the world?

We have 33 Plek Stations in 15 different countries, mostly in the USA. We also have another model, the Plek Pro. It is designed more for production, but also functions as a service machine. There are about 25 of these in existence.

Maybe you could say something about the difference between the PlekPro and the PlekStation?

The guitar is scanned

The difference is that the Plek Station is a machine for service and small-scale production. The major difference of the Pro is that it has a module that simulates string tension, meaning that you can work on an instrument without having to string it up. This makes a considerable increase in production speed possible. But the important thing is that we always measure the instrument under string tension, and this is what is always absolutely necessary, because that is what the calculation of the neck curvature and string action is based on.

3. What´s the standard of new guitar´s set up, fretwork, intonation at guitar shops in general?

Well, there is no standard really. This is something which depends a lot on the person doing the setup and there are a lot of ideas about this, some of which go in the wrong direction. For example that you should use the truss rod to adjust string action. Of course you can change the action when you adjust the truss rod, but it has very negative effects on fret buzz when playing.

I guess it also depends on the make of guitar you are dealing with?

It depends on the make, it depends on the gauge of the strings. In principle strings behave differently depending on their gauge. The greater the string tension, and this depends on the gauge of the string, the less the string is able to vibrate. In practice this means that with a set of very heavy gauge strings I can go for a much lower action without buzz than when I have very light strings, for example 9 or 8, they need a much higher action to produce a clean tone given the same attack. Then you can also fundamentally differentiate between electric and acoustic guitars. For acoustic guitars the tendency towards a somewhat higher action is determined by the fact that players usually create more dynamics directly from the instrument. With electric guitars this can be less because a lot of volume is created by the amplifier. An extreme example of this is with classical guitars. Here you can often only work with a very high action, because the entire dynamic range of the instrument is utilized to a particularly high degree.

Checking the initial scan

There are probably some shops who don't do much in the way of setup on new guitars....

This is always a question of what is done to a guitar before it is bought by the customer. When the instruments leave the factory they are often in quite an uncertain state and may change over time, through transport, the working of the wood, different atmospheric conditions in rooms, different climatic conditions, humidity, temperature. So what the customer gets is often a question of who has undertaken the final setup.

What would you expect from a first-class guitar shop as setup for a new guitar?

The customer expects a new guitar to play superbly, from his or her own perspective. It shouldn't buzz. That's what a player expects. But this brings us back to the point that there is currently no real standard for this to guide you. This a subject Plek looks at closely, because we are able to objectively measure an instrument and to repeat a setup on a different instrument, or again on the same instrument. A customer can have the same setup on a different guitar, that is something that is very precise and repeatable. It is a very important aspect that we can transfer a setup exactly to another instrument, because we have very precise measurement data, and that is a great advantage for the player.

Scan results before processing. Click to enlarge the image.

4. What´s possible to do on a Plek station that cannot be done by hand by a skillful guitar tech?

Basically speaking it is possible for the best luthier on his best day to reach the quality that the Plek machine achieves in the form of setup. That is a rare thing, and also a matter of luck. The difficulty of achieving an optimal setup has, among other things, to do with string tension and the fact that when you take the strings off a guitar, the neck changes in quite an extreme way, and the ideal curve is no longer there. That is the most difficult part – calculating that beforehand and planing this ideal line into the fretboard. Added to this is the fact that the ideal neck curvature for the lower strings is different to that for the higher ones. This means that each string has its own ideal neck curvature, if you want to do things optimally. This is a problem that it is very difficult to deal with by hand, and which can often be a matter of luck.

Does this mean that a fretboard needs to be planed differently according to the gauge of the strings above it?

The same scan, this time taken together with all strings. Click to enlarge

Ideally, the surface of the frets needs to be adapted to the string. When the fretboard does not possess this ideal line, the frets end up having different heights. It depends on the surface of the frets. If this effect is very strong, then you can have problems with frets that are very low in some places and very high in others. In this case the machine can do a re-fret by cutting the desired form directly into the fretboard, which in principle is the same thing as when you work on a fretless instrument.

So it is very difficult for a normal luthier to reproduce this without a Plek machine?

Yes, because the same rule applies: If you want to do it really well, it has to be done under string tension. And this is what the machine can do. It measures under string tension and can perform an optimal setup on the fretboard under string tension.

5. Speaking of playability and critical points on a guitar from your point of view. Are there any weak points that could be improved. Hardware, frets, fingerboards etc?

Scan results after Plek processing. Current fret curve and optimal fret curve are now the same.

Fundamentally speaking, you need to use good material to make a good guitar, in particular, good wood, good wood for the fretboard. Some types of wood have become very rare, or are not allowed for use in guitar making. In such cases we need to think more about what we can use to replace these materials. There is a lot of very good hardware available and you can get very high-quality parts for instruments.

Are there any typical weak points?

Weak points arise when the hardware is of substandard quality, for example when tremolos are used that are not up to the job, or gears that stick and jam. Gears are import for the tuning quality of an instrument. If you play Floyd Rose it's very important that the nut is good and well setup. The nut and the bridge are extremely important parts and need to be of good quality. If they are not set up properly you will get side-effects such as problems with intonation, open strings will sound dull, you'll get sitar effects. All this usually has to do with the quality of nut and bridge. By quality I mean that the material has to be good and the setup in the nut has to be good, that is to say that the nut slots have to be cleanly cut, precisely shaped, have the right height. Otherwise you get intonation problems when the nut is too high.

And what about frets?

There is a lot of good fretwire available on the market. Again, the question here is: what is the quality of the fretwork? Fretwork is a real art. How precisely have the frets been built into the guitar. Are they loose or well-fitted? It not so much to do with the material but rather a question of the quality of the work. There is a lot of room for improvement here, and it is an area that we have a lot of experience in because we see a lot of instruments that have faulty fretwork.

Scan results after processing for all strings.

And the typical problems on the fretboard and neck?

The truss rod. Truss rods often don't work properly or are very difficult to get at. Or maybe the basic setup for a truss rod is incorrect. The truss rod might be loose and the neck is still bent backwards, and I can't loosen it any further. Those are problems that happen time and again, and usually require a lot of work, maybe even a complete refret.

Also the profile of the fretboard should come as close as possible to the ideal form of the surface of the frets. The fretboard should be so well prepared that when the frets are dressed they are as uniformly high as possible. That is the pre-condition for a fretboard.

Can you say something about compound falloff / compound radius?

This is a very important aspect, particularly for fretboards that have a very small radius. And for players who like to bend their strings. When I bend a string and the radius is very small, it means that I have to bend it “over the hill”. The curvature of the fretboard produces a mound that the string has to go over. The whole thing gets particularly complicated when the string is very long. I don't mean the length of the part of the string that vibrates, but the length of the string as a whole. That is enormously important. For example if the string is attached to the last gear on the headplate of the guitar, that might be ten centimeters, and then another ten or fifteen from the bridge to the string ends, so the string is effectively 25 centimeters longer. The result is that when I bend the string, I have to pull a lot further to get the note I want. The effect is increased because I have to pull the whole string, and the string has to go up an ever bigger hill. The danger is that tone dies, and that the playability is reduced. That is one of the most important experiences that we make, that there are a lot of instruments that have this kind of radius, and correcting these faults is a major challenge.

How does the Plek machine deal with this kind of problem?

Basically speaking, the Plek machine can optimize existing conditions by correcting the radius, the frets, to the extent permitted by the height of the frets. And via the so-called fall-off where it is possible to shape the conditions in an optimal way for this particular instrument. In extreme cases you have to raise the action, that always works, but that has well-known disadvantages. Raising the action always means it's more difficult to play, intonation problems, etc.

6. In your mind, are there any brands that stand out with regard to playability, set up and intonation?

I don't really want to talk about individual brands, it's not really in my interest to make a judgment here. We see a lot of very different instruments. The quality does not always depend on the price.

OK, but I'm sure you have your own favorite brands. What are the characteristics of an excellent guitar, in your opinion?

For me it is on the one hand a question of how the instrument feels, the sound, for my way of playing. What does it look like? I have my own personal favorite brand, sure. But for me personally it is the playability that plays an enormously important role. When you play an instrument you produce a million notes, and the feeling that I don't have to fight the instrument, that every note sounds true, that the surface of the frets is right, that the crowning is right, that is what I personally would see as defining the quality of an instrument.

7. Any bad examples?

I am always having instruments sent to me in our workshop where you find the whole spectrum of buzzing, poor playability, loose frets, perhaps even causing more or less unplayable notes if they are really loose. If frets start vibrating along with the string the tone dies or is totally dull. We see instruments that are so wrong in their basic setup that they are essentially unplayable.

The process is basically the same for electrics and acoustics. Electric guitars tend to have lower setups, lower actions than acoustics. This is to do with the playability and the dynamics, which are less extreme than on an acoustic. Once again, on a classical guitar this is particularly clear, because the classical guitar requires a very high setup. One exception to this is flamenco guitars. They are usually equipped with a very low setup, that's because the players want a certain degree of buzz, that's part of the flamenco sound. But in all cases the Plek process is essentially the same. What we are talking about here are parameters that can be configured. Neck curvature occurs automatically in relation to string action, and here again, depending on the player, the string gauge, the player's attack, the setup follows the same principles on any instrument. The tendency is for string action to be higher on acoustics and even higher on classical guitars, because it results from the dynamics of the instrument. For example with an acoustic guitar, players tend to have a harder attack, because they want a powerful sound. But the sound is very short, because the energy is dissipated in volume. By contrast an electric guitar can have a very long sustain, so it's a different feeling when playing the guitar. This is in part also a result of the difference in action. But the basic principles are the same. The creation of sound on a guitar, which can be very complex with all the overtones of the instrument, in principle always follows the same rules, and this determines the behavior of the instrument.

9. What about curved frets on a True Temperament guitar. Is that possible to Plek?

At the moment we have examples of True Temperament guitars in our workshop, and it's on our to-do list. So it's at the planning stage at the moment. But we can already scan and analyze True Temperament guitars. We can measure them, and can then work on them by hand. And then we can measure them again, to confirm our work. So yes, we can do work on True Temperament guitars, but it's currently still a lot more work than the fully automatic process. Of course it is still a gain that we can scan the instrument, but crowning is actually the tricky part.

10. What´s the next step in the Plek development?

Intonation. To be able to replace frets for different intonation systems. As we all know there is not only one idea of where the positions of the frets are supposed to be, what is the real length of the string, etc. There are many ideas about this. Plek plans to be a tool so that any scale can be realized, independently of the idea behind it. The principle is that you can tell a formula to the Plek machine and the machine uses the formula to calculate the position of the frets.

So this is a tool that can make recommendations for guitar making, guitar production?

Yes it is a kind of universal tool for all available scales, like for the piano, where there are a lot of different tunings that exist simultaneously. Same thing for the guitar. For example you have True Temperament, that's an extreme example, but also Fan Frets, Wave Frets, the Buzz Feiten system, Novomensur, many different scales – just think of Fender and Gibson, who use different scales. One of our aims is to make the different scales available to Plek operators, who can then choose the scale they want to work with.

Anything else you want to tell us about?

Another thing is a function for fretless instruments and to refret instruments, enabling us to plane the fingerboard in the same way as the surface of the frets. This already exists in the Plek, every Plek machine can do it.

And what direction do you think Plek is going in the future?

One part we see is that there will be a standard of setup for everybody. So that players really have an idea of how to get their setup and how to communicate their setup because they know what they are talking about. If you say “I'm playing 10-46 and my setup is 2mm at the low E string and 1.1 at the high E string, this is a setup which is defined, and that can be reproduced, so that we know exactly what the setup is. Or take the setup of famous players. It will be possible to make this available to the market, and to transfer this setup to other instruments using the measurement data that we have acquired. That is a really big potential!